The invention relates generally to breakwater devices, and more particularly, it concerns an improved breakwater apparatus adapted to be anchored to minimize roll of the apparatus and a method for anchoring a breakwater apparatus to minimize roll of the apparatus.
In my prior patent, U.S. Pat. No. 3,800,543, I described an offset breakwater configuration that was believed to be a significant improvement over existing breakwaters. The breakwater configuration described in that patent included substantially vertical wave reflecting surfaces which were positioned relative to each other and relative to on-coming waves such that the horizontal force effect of the on-coming waves could be substantially balanced and cancelled. This patent and the teachings included therein are hereby fully incorporated by reference.
The principle behind the breakwater configuration described in my prior patent related to the positioning of vertical wave surfaces such that the wave surfaces were disposed in two substantially parallel planes separated from each other by a distance approximately equal to one-half the wavelength of the anticipated on-coming waves. As explained therein, such configuration caused the crest of the wave to strike the surfaces contained in one plane at the same time that the trough of the wave was striking the surfaces contained in the other plane. Since the water behind the two planes remained substantially level, this configuration resulted in opposing horizontal force components on the two planes which substantially cancelled each other out. The proportion of the wave form transmitted through the breakwater was thereby substantially reduced--yielding an improved design for a breakwater for minimizing waves behind the breakwater.
While the breakwater configuration described in U.S. Pat. No. 3,800,543 is believed to be a significant improvement over prior breakwaters, it has been determined that still more improvement may be provided. Specifically, it has been observed that the mooring lines or anchor lines typically used to secure such breakwaters in deep water can introduce additional force components which may cause the breakwater to roll and thereby transmit wave motion behind the breakwater. Similarly, because of the varying profiles in forces exerted by waves on the breakwater device, it is possible that the component of roll may be enhanced. It is therefore desirable to provide a breakwater device which incorporates the advantages of the breakwater configuration described in U.S. Pat. No. 3,800,543, while at the same time minimizing roll of the breakwater such that the proportion of the wave form transmitted through the breakwater is even further minimized.